Monofilament threads were hitherto produced in the prior art by employing a spinning process or or in the pressure nozzle process. It is not possible using the prior art processes to introduce reinforcing cores into the monofilament threads which have the required stabilizing factors and which show no effect with respect to the cold flow of the plastic. Fish nets, for example, were hitherto woven from monomers containing a polyamide group as monofilament nylon threads. Such nets must be used in fishing grounds the waters of which are at extremely low temperatures, where the plastic, however, is disadvantageous in that it thereby becomes brittle.
Furthermore, ship's cables with a diameter between 200 and about 650 mm are made from hemp. These hemp threads, however, are subject to rotting because of their exposed condition and have to be renewed about annually.
If it is desired, with the use of molds, to coat cores with plastic, this cannot be successfully accomplished in the case of thin threads and also it is not possible to achieve this coating of the cores continuously.